refactor+feat: allow subsystems to send only declared messages, generate graphviz (#5314)

Closes #3774
Closes #3826

polkadot/node/core/runtime-api/src/lib.rs

@@ -25,8 +25,7 @@
 use polkadot_node_subsystem::{
 	errors::RuntimeApiError,
 	messages::{RuntimeApiMessage, RuntimeApiRequest as Request},
-	overseer, FromOverseer, OverseerSignal, SpawnedSubsystem, SubsystemContext, SubsystemError,
-	SubsystemResult,
+	overseer, FromOverseer, OverseerSignal, SpawnedSubsystem, SubsystemError, SubsystemResult,
 };
 use polkadot_primitives::{
 	runtime_api::ParachainHost,
@@ -92,12 +91,11 @@ impl<Client> RuntimeApiSubsystem<Client> {
 	}
 }
 
-impl<Client, Context> overseer::Subsystem<Context, SubsystemError> for RuntimeApiSubsystem<Client>
+#[overseer::subsystem(RuntimeApi, error = SubsystemError, prefix = self::overseer)]
+impl<Client, Context> RuntimeApiSubsystem<Client>
 where
 	Client: ProvideRuntimeApi<Block> + Send + 'static + Sync,
 	Client::Api: ParachainHost<Block> + BabeApi<Block> + AuthorityDiscoveryApi<Block>,
-	Context: SubsystemContext<Message = RuntimeApiMessage>,
-	Context: overseer::SubsystemContext<Message = RuntimeApiMessage>,
 {
 	fn start(self, ctx: Context) -> SpawnedSubsystem {
 		SpawnedSubsystem { future: run(ctx, self).boxed(), name: "runtime-api-subsystem" }
@@ -333,6 +331,7 @@ where
 	}
 }
 
+#[overseer::contextbounds(RuntimeApi, prefix = self::overseer)]
 async fn run<Client, Context>(
 	mut ctx: Context,
 	mut subsystem: RuntimeApiSubsystem<Client>,
@@ -340,8 +339,6 @@ async fn run<Client, Context>(
 where
 	Client: ProvideRuntimeApi<Block> + Send + Sync + 'static,
 	Client::Api: ParachainHost<Block> + BabeApi<Block> + AuthorityDiscoveryApi<Block>,
-	Context: SubsystemContext<Message = RuntimeApiMessage>,
-	Context: overseer::SubsystemContext<Message = RuntimeApiMessage>,
 {
 	loop {
 		select! {